Angres B, Müller A H, Kellermann J, Hausen P
Max Planck Institut für Entwicklungsbiologie, Tübingen, Federal Republic of Germany.
Development. 1991 Mar;111(3):829-44. doi: 10.1242/dev.111.3.829.
Using a cadherin fraction from Xenopus tissue culture cells as an immunogen, two monoclonal antibodies were obtained that allowed the characterization of two distinct cadherins in the Xenopus embryo. The two cadherins differ in molecular weight, in their time of appearance during development and in their spatial pattern of expression. One of the antigens was identified as E-cadherin. It appears in the embryonic ectoderm during gastrulation when epidermal differentiation commences and it disappears from the neural plate area upon neural induction. The second antigen could not be allocated to any of the known cadherin subtypes and was termed U-cadherin. It is present in the egg and becomes deposited in newly formed inner cell membranes during cleavage, the outer apical membranes of the embryo remaining devoid of the cadherin throughout development. U-cadherin is found on membranes of all cells up to the late neurula stages. A conspicuous polarized expression of the antigen on the membranes of individual inner cells suggests its participation in the segregation of cell layers and organ anlagen. These findings are discussed in the context of current hypotheses on the role of cadherins in establishing the spatial structure of the embryo.
利用非洲爪蟾组织培养细胞中的钙黏蛋白组分作为免疫原，获得了两种单克隆抗体，这使得对非洲爪蟾胚胎中两种不同的钙黏蛋白进行表征成为可能。这两种钙黏蛋白在分子量、发育过程中出现的时间以及表达的空间模式上存在差异。其中一种抗原被鉴定为E-钙黏蛋白。它在原肠胚形成期间出现在胚胎外胚层，此时表皮分化开始，并且在神经诱导后从神经板区域消失。第二种抗原无法归类到任何已知的钙黏蛋白亚型，被命名为U-钙黏蛋白。它存在于卵中，并在卵裂期间沉积在新形成的内细胞膜上，在整个发育过程中胚胎的外顶端膜一直没有这种钙黏蛋白。直到神经胚后期，在所有细胞的膜上都能发现U-钙黏蛋白。该抗原在单个内细胞膜上明显的极化表达表明它参与了细胞层和器官原基的分离。这些发现是在当前关于钙黏蛋白在建立胚胎空间结构中作用的假说背景下进行讨论的。
